1. Field of the Invention
The present invention relates to a nonvolatile memory device and an organic lighting emitting diode display device (OLED display device) including the same. More particularly, the present invention relates to a nonvolatile memory device including a semiconductor layer having a drain region which may be shallowly doped compared to a source region, and a tunnel oxide layer which may be thin in regions corresponding to the source and drain regions and thick in a region corresponding to a channel region, a method of fabricating the same, and an OLED display device including the same.
2. Description of the Related Art
In general, memory devices may be divided into two types. One type may be a volatile memory device in which stored data may be erased when power is interrupted. The second type may be a nonvolatile memory device in which the stored data may be maintained even when power is interrupted. A dynamic random access memory (DRAM) and a static random access memory (SRAM) are typical examples of the volatile memory device, and a flash memory is a typical example of the nonvolatile memory device.
A flash memory may be fabricated by sequentially stacking and then etching a tunnel oxide layer, a floating gate, an upper gate insulating layer, and a control gate on a semiconductor substrate.
The floating gate may be isolated between the tunnel oxide layer and the upper gate insulating layer, and the floating gate may store, erase or read information according to a voltage supplied to the control gate.
The flash memory may be formed on a wafer substrate formed of single crystalline silicon which has excellent memory characteristics. However, the flash memory additionally may include a connection apparatus or structure to be combined with another device, e.g., a display device.
During programming, a general flash memory may be easily damaged at an interface between a tunnel oxide layer and a semiconductor layer. During erasing, a relatively higher voltage than in writing or reading may be supplied to a control gate. As a result, flash memory technology which is less liable to damage is desirable for memory devices.